The present invention relates generally to composition and method for improving combustion and reducing polluting emissions in fuels.
The interest in improving fuel efficiency has become paramount as our natural resources dwindle and the cost of fuel continues to rise. Fuel efficiency and improved emissions characteristics can be improved by adding a fuel additive to hydrocarbon fuels. Several existing fuel additives are known to increase fuel efficiency, for example, U.S. Pat. Nos. 4,274,835, 5,826,369, and 6,193,766 describe fuel additives that improve combustion. Despite the successes of these inventions, there still remains a need for fuel additives that improve combustion.
When hydrocarbon based fuels are combusted, various pollutants are generated. These combustion products include particulates, carbon monoxide, nitrogen dioxide, sulfur dioxide, and lead (where leaded fuels are still in use). Ozone is also a pollutant (although not directly produced) that results from unburned hydrocarbons. Both the U.S. Environmental Protection Agency (EPA) and the California Air Resources Board (CARB) have adopted ambient air quality standards directed to these pollutants. Both agencies have also adopted specifications for lower-emission gasolines and diesel fuels.
In response to these legislative efforts, producers of hydrocarbon fuels, for example gasoline, diesel, jet and the like, have attempted to readjust refinery processes so as to produce base fuels meeting these more rigid specifications. Such an approach suffers from a number of drawbacks, including the high costs involved in reconfiguring a refinery process, reduced production of the refinery, and the like. Accordingly, fuels that do not suffer these and other related economic drawbacks are highly desirable.
Hydrocarbon fuels typically contain complex mixtures of hydrocarbons, depending on the specific application: including but not limited to gasoline, diesel, jet, fuel oils, coal fuels, resid fuels, kerosene, and the like. Fuels typically may also contain other additives, including detergents, anti-icing agents, emulsifiers, corrosion inhibitors, dyes, deposit modifiers, ignition modifiers and non-hydrocarbons, for example oxygenates, for improving the emission characteristics of fuels.
It would be desirable to find compounds that have a positive effect on reducing the emissions characteristics of burnt hydrocarbon fuels. The improvement in burning (combustion such as in a jet, diesel, or gasoline engine) and emissions characteristics can be correlated to certain fuel burning testing procedures. The Smoke Point of certain fuels, including additives, can be tested using ASTM test D 1322-90 Standard Test Method for Smoke Point of Aviation Turbine Fuels. This testing procedure is hereby incorporated by reference. In particular, the test of Smoke Point can be used to show the effect of additives on a standard jet engine fuel such as A, 1, JP-4 or JP-8 (herein after all known as “Jet”) that exhibit a reproducible height of a smokeless flame when burned in wick-fed lamp of the ASTM test. This test is qualitatively related to the potential radiant heat transfer from the combustion products of the fuel. Additives incorporated into a fuel that improve the combustion characteristics, that is completeness of burning, exhibit a higher smoke point. This effect can be synergistic and unexpected for certain additives that have not been previously known as additives to Hydrocarbon fuels for this purpose. When improvements in Smoke Point are found this positively correlates to reducing polluting emissions into the environment. As reduced emissions are desirable, there is an ongoing need for HC fuels that incorporate new and useful additives to accomplish the same. Accordingly, the present invention provides solutions to this ongoing problem of polluting emissions from various internal combustion devices, for example, automotive engines, diesel engines (so-called piston engines), coal burning plants, aero-engines, jet engines, two-stroke engines, and the like, thereby overcoming many of the aforementioned limitations in the hydrocarbon fuel formulation art.